Zone air conditioning system



Nov. s, 1938. A. c. GRANT -2,' 3' ,336)

ZONE AIR CONDITIONING SYSTEM Filed Dec. 31, 19:54

Arthur 0. iant auto (Mu;

gwoentoo v Patented Nov; 8, 1938 ZONE AIR CONDITIONING SYSTEM Arthur C.Grant, St. PauL'Minn assignor to Minneapolis-Honeywell RegulatorCompany, 1 Minneapolis, Minn., a corporation of Delaware ApplicationDecember 31, 1934, Serial No. 759,918

11 Claims.

' This invention relates to zone air conditioning systems for usein-buildings where it is desirable to differently condition variousrooms or groups of rooms.

In conditioning buildings and especially in houses it is desirable tohave certain rooms such as the living room, dining room and librarymaintained at a certain. temperature and relative humidity while it isdesirable to have other rooms such as bedroomsand servants quartersmaintained at another temperature. This is also true for summer cooling.as well as for winter heating. I

It is therefore an object of this invention to provide a novel zone airconditioning system whereby certain rooms of a building are maintainedat one condition and the other rooms at another condition.

Another object of this invention is to provide 20 a novel zone airconditioning system wherein certain rooms of a building are conditionedby means of an air conditioning unit and other rooms are conditioned bydirect radiation.

A further object is to provide an automatic zone air conditioning systemfor winter heating and for summer cooling whereby various rooms I of abuilding are maintained at difierent conditions and wherein theconditioning system may be readily changed from winter heating to sum-30 mercooling operation.

' Another object is to provide a zone air conditioning system having anair conditioning unit for certain rooms of a building and directradiation means for other'rooms wherein the air,

conditioning unit and the direct radiation means are independentlycontrolled and wherein a common circulating means is used to circulateconditioning fluid through the air conditioning unit and the directradiation means.

Other objects and advantages will become apparent to those skilled inthe art by reference to the accompanying specification, claims anddrawing in which drawing there is diagrammatically shown the zone airconditioning system of this invention.

The invention is shown and described as a conditioning system for fourrooms A, B, C and D. Rooms C and D which are the rooms mostly used, suchas a living room, dining room and study in a domestic building areheated or cooled and humidified by means of an air conditioning unit.The rooms A and B which are remote and not used as often as the rooms Cand D such as bedrooms and servants quarters are heated or.

55 cooled by direct radiation. The term fidirect radiation is used todistinguish conditioning by radiators from conditioning by an airconditioning unit. Various types of radiators, such as exposed, enclosedor shielded, may be used for conditioning and the manner of conditioningcaused thereby is termed for purposes of illustration as directradiation.

- Although heatmay be obtained from any source, for purposes ofillustration, the heat is generated in a hot water boiler III which maybe gas-fired, the gas entering the boiler ill from some source not shownthrough a pipe l2. Located in the pipe I! is a gas control valve Ii forcontrolling the supply of gas to the boiler ill. The gas valve is movedto open position by energizing a solenoid or motor mechanism i3 and upondeenergization thereof the valve H is closed. Located on the boiler iiiin such a manner as to respond to changes in temperature in the boileris a conventional boiler thermostat i4 which is secured in place bymeans of a. binding post ii. The thermostat Hi carries a contact i5which is moved into engagement with a stationary contact I 6 when theboiler temperature drops below a predetermined value and which is movedout of engagement with the contact l6 when the boiler temperature risesabove the predetermined value. Wires I8 and I9 lead from some source ofpower, not shown, the wire l8 being connected to a manually controlledswitch arm 20 and the wire l9 being connected to the solenoid or motormechanism l3. The manually operated switch arm 20 is adapted to engage acontact 2i which is connected by means of a wire 22 to the binding postI! of the thermostat M. The stationary contact i6 is connected by meansof a wire 23 to the solenoid or motor mecha-' nism i3.

When the control means for the boiler I is to be placed in operation forwinter heating, the switch arm 20 is moved into engagement with thecontact 2i. When the temperature 'of the boiler i0 is below apredetermined value, contact l engages contact Hi to complete a circuitfrom wire l8, switch arm 20, contact 2i, wire 22, binding post ii,thermostat i4, contact i5, contact [6, wire 23 and solenoid l3 to wireiii to energize the solenoid i3 to open the valve II to admit gas to theboiler III to raise the tempera-- ture of theboiler' l0. When thetemperature of the boiler l0 reaches the predetermined value, thethermostat i4 moves the contact i5 out of engagement with the contact isto break the above circuit to deenergize the solenoid l3 to olose thevalve Ii to stop firing of the boiler. In

this manner, the heating fluid in the boiler I is maintained at aconstant temperature.

Connected to the top of boiler I0 is a hot water supply pipe 25, havinga manually operated shutofi valve 26 located therein. The supply pipe 25is connected to a four-way connection 21. Also, connected to thefour-way connection 21 is a pipe 28 having a control valve 29 locatedtherein, said control valve 29 being moved to open or closed positionsby means of a reversible electric motor 24 having the usuallimitswitches containedtherein. The pipe 28 connects to a pipe 30 andrisers 3| extend upwardly therefrom and are con nected to radiators 32located in rooms A and B. Return risers 33 extend downwardly from theradiators 32 located in rooms A and B and connect into a pipe 34 whichcontains a four-way connection 35. A circulating pump designated at 31is operated by an electric motor 44 and .a pipe 36 connects the four-wayconnection 35 to the circulating pump 31. A pipe 38 connects thecirculating pump 31 with the boiler H] toreturn water from the radiators32 to the boiler II] to be reheated therein. Located in the pipe 38 is amanually controlled shut-off valve 39. When the manually controlledshut-off valves 26 and 39 and the control valve 29 are opened and thecirculating pump 31 is placed in operation, hot water will be circulatedfrom the boiler |U through the radiators 32 to cause heating of therooms A and B by direct radiation.

Connected to the four-way connection 21 is a pipe 46 leading from somesource of cooling medium and a manually controlled shutofi valve 4| islocated in this pipe 46. Connected to the pipe 38 between thecirculating pump 31 and the shut-off valve 39 is a pipe 42 leading tothe source of cooling medium and having located therein a manuallycontrolled shut-01f valve 43. The cooling medium supplied to the pipe 48may emanate from any known source such as a mechanical refrigerationsystem, an ice cooling system or a city water supply system. By closingthe manual shut-off valves 26 and 39 and by opening the manuallyoperated shut-off valves 4| and 43, cooling fluid is supplied to thesystem for summer cooling instead of heating fluid from the boiler l8.With the shut-off valves in the positions just described, and if thevalve 29 is opened and the circulating pump 31 is put in operation,

cooling fluid will be circulated through the radiators 32 in the rooms Aand B to cool the same by means of direct radiation. From the above, itis seen that the radiators 32 may either heat or cools the rooms A and Bby direct radiation, depending upon whether the rooms should be heatedor cooled by manually manipulating the manually controlled shut-offvalves 26, 39, 4| and 42.

An air conditioning unit of any known type, having a heat exchanger 46located therein is designated at 45. The heat exchanger 46 is connectedby means of a pipe 41 to the four-way connection 21 and by means of apipe 48 to the fourway connection 35. When the circulating pump 31 isput in operation, heatingfluid or cooling fluid is circulated throughthe heat exchanger 46 depending upon the positions of the shut-offvalves 26, 39, 4| and 43. Air is passed over the heat exchanger 46 bymeans of a, fan 49 driven by an electric motor by means of a belt 56.The air is drawn through filters 52 and passed over the heat exchanger46 and is conducted by means of ducts 53 through registers 54 into therooms C and D. Located above the heat exchanger 46 in the airconditioning unit 45 is a humidifyins device of any known typeillustrated as a spray device 55, which is supplied with Water through apipe 58 from some source not shown. The

supply of water to the humidifying spray device 55 is controlled bymeans of a valve 56 which is opened by energizing a solenoid or motordevice 51 connected thereto and which is closed by deenergizing thesolenoid 51.

From the above, it is seen that heated or cooled air is supplied to therooms C and D, depending upon whether the rooms C or D should be heatedor cooled and also that the humidity of the air so supplied iscontrolled by means of the humidifying spray device 55. 4

Located in the room A is a room thermostat 60 which is mounted foroperation on a binding post 6|. The thermostat 60 carries a contact 62which is selectively moved into and out of engagement with contacts 63and 64. Contacts 63 and 64 are connected by means of wires 69 andrespectively to switch arms 65 and 66 respectively of a double throw,double-poled reversing switch. The switch arms 65 and 66 when moved tothe right are adapted to engage respectively the contacts 61 and 68 andwhen moved to the left are adapted to engage respectively the contacts68 and 61'. 1| and 12 are line wires that lead from some source of powernot shown and which are connected to opposite ends of a, primary 13 of astep-down transformer 14. One end of the secondary of the step-downtransformer 14 is connected by means of a wire 16 to the binding post 6|of the thermostat 60. The other end of the secondary 15 is connected bymeans of a wire 11 to the electric motor 24. The contacts 61 and 68 ofthe reversing switch are also connected by means of wires 18 and 19respectively to the electric motor 24. I

Assume that the valve 29 is held in a closed position by means of theelectric motor 24, that the switch arms 65 and 66 of the reversingswitch are in engagement with the contacts 61 and 68 'and that thesystem is conditioned for winter heating operation. When the roomthermostat 60 calls for heat, the contact 62 thereof is moved intoengagement with the contact 63 thereby completing a valve openingcircuit from the secondary 15 of the step-down transformer 14 throughwire 16, binding post 6|, thermostat 66, contacts 62 and 63, wire 69,switch arm 65, contact 61, wire 19, electric motor 24 and wire 11 backto the secondary 15 of the step down transformer 14. Upon completion ofthis circuit, the electric motor 24 is operated in one direction to openthe control valve 29 to permit circulation of the heating fluid throughthe radiators 82 of rooms A and B to heat these rooms A and B by meansof direct radiation. When room A has become sufficiently heated, thethermostat 66 moves the contact 62 thereof into engagement with thecontact 64, thereby completing a valve closing circuit from thesecondary 15 of stepdown transformer 14 through wire 16, binding post6|, thermostat 60, contacts 62 and 64, wire 10, switch arm 66, contact68, wire 18, electric motor 24, and wire 11 back to the secondary 15 ofthe step down transformer 14. Upon completion of this circuit, theelectric motor 24 is operated in the reverse direction to move the valve29 to a closed position to stop circulation of the heating fluid throughthe radiators 32.

Assume now that the shut-oil valves 26, 39, 4| and 43 are positioned forsummer cooling operation, that the reversing switch has also beenpositioned for summer operation by causing engagement of switch arms 85and 66 with contacts 68' and 61' respectively, that control valve 28 isin a closed position and that the temperature of the room A rises above"a predetermined value. Upon such rise in temperature, thermostat 88moves the contact 82 into engagement with contact 84 to complete acircuit from secondary 15 of the step-down transformer 14 through wire18, binding post 6], thermostat 88, contacts 62 and 64, wire 18, switcharm'88, contact 81', wire 18, electric motor 24 and wire 11 back to thesecondary 15 of thestep-down transthe secondary 15 of step-downtransformer 14 through wire 16, binding post 8|, thermostat 88,

contacts 62 and 63, wire 68, switch arm 65, contact 68', wire 18,electric motor 24, and wire 11 back .to the secondary 15. The completionof this circuit causes reverse energization of motor 24 to move thevalve 28 into closed position to. stop circulation of the cooling fluidto the radiators 32. 1

Electric motor 24 also operates a lever 8| which carries a mercuryswitch 82 of the usual type having a pair of electrodes located thereinwhich are contacted by means of the usual mercury upon thetilting of themercury switch 82 to a given position. When the valve 28 is closed, thearm 8| is in the down position as shown in the drawing and the mercuryin the mercury switch 82 is out of engagement with the electrodes ofmercury switch 82. In other words, when the valve 28 is closed, themercury switch 82 is in open circuit position. When the valve 28 ismoved to open position by the electric motor 24, the lever 8I is movedupwardly to tilt the mercury switch 82 into circuit closing position.

Leading from some source of power not shown are line wires 83 and 84.One of the electrodes of the mercury switch 82 is connected by means ofa wire 85 to the line wire 83. The other electrode of mercury switch 82is connected by means of wires 86 and 81 to the electric motor 44 whichdrives the circulating pump-3L The electric motor 44 is in turnconnected by means of wires 88 and 88 to the line wire 84.

When the valve 28 is moved to an open position, the mercury tube 82 istilted to cause the mercury contained therein to engage theelectrodes'thereof to complete acircuit from the line wire 83 throughwire 85, mercury switch 82, wire 88, wire 81, electric motor 44, wire 88and wire 88 back to the line wire 84. Upon completion of this circuit,the electric motor 44 is energized to cause operation of the circulatingpump 31. When the control valve 28 is moved to a closed position by theelectric motor 24, the mercury switch 82 is tilted to the open circuitposition thereby breaking the above mentioned circuit to stop operationof the electric motor 44 to stop operation of the circulating pump 81.

From the above, it is seen that when the system is set for winteroperation in the manner described and when the room thermostat 88 callsfor heat, the control valve 28 is opened and the motor 44 is energizedto operate the circulatingipump 31 to cause circulation of the heatingfluid from the boiler I8 through the radiators a: to cause heating ofthe rooms A and B by direct radiation and that when the temperature ofthe room rises above a predetermined value, the control valve 28 isclosed and the circulating pump 81 is stopped to prevent circulation ofthe heating fluid through the radiators 32. It is also seen that whenthe structure as set out above is set for summer operation, that is forcooling, and when the temperature of the room rises above apredetermined value, the control valve 28 is opened and the circulatingpump 31 is operated to cause circulation of the cooling fluid to theradiators 32 to cool the roomsA and B by direct radiation and that when"the temperature in'the room lowers below'a predetermined value, thecontrol valve 28 is closed and the circulating pump 31 is stopped toprevent circulation of the cooling fluid through the radiators 32.

Located in the room C is a room thermostat 8I supported for operation ona binding post 82. The room thermostat 8| selectively moves a contact 88into engagement with either contact 84 or contact 85. Contact 84 isconnected by means of a wire 88 to a switch arm 88 of a reversing switchand contact 85 is connected by means of a wire 81 to a switch arm 88 ofthe reversing switch. The switch arms 88 and 88 of the reversing switchare moved selectively.

into engagement withcontacts I88 and.I8I or contacts MI and I88respectively.

A double coil relay comprises an energizing coil I02 and a bucking orneutralizing coil I83. The relay is operatively connected to switch armsI84, I85 and I88 to rnove these switch arms into engagement withcontacts I81, I88 and I88 respectively upon energization of theenergizingv coil mally held out of engagement with the contacts I81, I88and I88 by a biasing means such as gravity, springs or other means notshown. Upon energization of the energizing coil I82, the switch arms aremoved into engagement with their respective contacts against the bias ofthe opening means and upon energization of the neutralizing or buckingcoil I83 which neutralizes the pulling efl'ect of the energizing coilI82, the switch arms are moved out of engagement with their respectivecontacts by the biasing means which tends to maintain the switches inopen position.

- Line wires leading from some source of power not shown aredesignated.at H8 and III and these wires are connected to opposite endsof a primary I I2 of a step-down transformer II 3. The step downtransformer I I3 is provided with a secondary II4 one end of which isconnected by means of a wire v I I5 to one end of the energizing ,coilI82. A wire I I8 also connects the same end of the energizing coil I 82with one end of the bucking or neutralizing coil I83. Theother end ofthe neutralizing coil I83 is connected by I82. The switch arms I84, I85and I86 are nor- I means of a wire II1 to the contact I M of thereversing switch. The contact I88 of the reversing switch is connectedby means of a wire II 8 and a wire II8 to the other end of the secondaryI I4 of the step-down transformer I I3. The other end of the energizingcoil I82 is connected by means of a wire I28 to the binding post 82 ofthe room thermostat 8|." The switch arm I84 is conter heating and ,thatswitch arms 98 and 99 are moved into engagement with contacts I and IOI.Upon a call for heat by the thermostat 9i, the contact 93 is moved intoengagement with the contact 94 thereby completing a circuit from thesecondary I I4 of step-down transformer II3 through wire II9, wire II9,contact I00, switch arm 99, wire 96, contacts 94 and 93, thermostat 9I,binding post 92, wire I20, energizing coil I02 and wire II back to thesecondary I I4. Upon completion of this circuit, the energizing coil I02is energized to move switch arms I04, I05 and I06 into engagement withcontacts I01, I08 and I09 respectively. Upon the engagementof switch armI 04 with contact I01, a holding circuit is completed from the secondaryII4 of step-down transformer II3 through wire II9, wire I2I, switch armI04, contact I 01, energizing coil I02 and wire II5 back to thesecondary II4. This holding circuit maintains the energizing coil I02energized to maintain the switches in engagement with their respectivecontacts even though the contact 93 of the room thermostat 9I is movedout of engagement with the contact 94.

Upon a rise in temperature above a predetermined value, thermostat 9Imoves the contact 93 into engagement with the contact 95 therebycompleting a neutralizing or bucking circuit from the secondary II4 ofstep-down transformer II3 through wire II9, wire I2I, switch arm I04,contact I01, wire I20, binding post 92, thermostat 9|, contacts 93 and95, wire 91, switch arm 99,

contact IOI, wire II1, bucking coil I03, wire II6 and wire II 5 back tothe secondary I I4. Upon completion of thisbucking or neutralizingcircuit, the bucking coil I 03 of the relay is energized to neutralizethe pulling effect of energizing coil I02 whereby the biasing meansmoves the switch arms I04, I05 and I06 out of engagement with thecontacts I01, I 08 and I09.

When the switch arms 96 and 99 are moved into engagement respectivelywith the contacts IOI' and I00 for summer cooling operation, the exactreverse action is accomplished. Upon a rise in temperature of the roomabove a predetermined value, the thermostat 9| moves the .contact 93into engagement with contact 95 to complete a circuit through thecontact I00 oi! the reversing switch to cause energization of theenergizing coil I02 01' the relay to cause closing of switches I04, I05and I06 with respect to the contacts I01, I08 and I09. By movement ofswitch arm I04 into engagement with the contact I01, a holding circuitis completed for the coil I02 of the relay as above. Upon a decrease intemperature below a predetermined value, the contact 93 is moved intoengagement with contact 94 by the thermostat 9I to complete a circuitthrough the contact I0'I' of the reversing switch to cause energizationof the bucking or neutralizing coil I03 which neutralizes the pullingeffect of the energizing coil I02 which allows opening of the switchesI04, I05 and I06 with respect to their contacts. I01, I09 and I09 bymeans of the biasing means.

Connected to the line wire III is a wire I23 which is in turn connectedto two wires I24 and I25. The wire I24 is connected to the contact I08and the wire I25 is connected to the contact I09. The switch arm I05which cooperates with the contact I08 is connected by means of a wireI26 and the wire 81 to the motor 44 which controls the operation of thecirculating pump 31. The motor 44 of the circulating pump 31 isconnected by means of the wire 88, a wire I21, a wire I28 and a wire I29to the line wire H0. The switch arm I06 which cooperates with thecontact I09 is connected by means of a wire I30 to the motor 5I whichoperates the fan 49 of the air conditioning unit 45 and the motor 5I isin turn connected by a wire I3I, the wire I29 and the wire I29 to theline wire IIO.

When the switch arms I05 and I06 are moved into engagement with thecontacts I09 and I09, an electric circuit is completed from the linewire III through wire I23, wire I24, contact I09, switch arm I05, wireI26, wire 91, electric motor 44, wire 98, wire I21, wire I29 and wireI29 to the line wire IIO to cause energization of the electric motor 44to cause operation of the circulating pump 31. Another circuit is alsocompleted from the line wire III, through wire I23, wire I25, contactI09, switch arm I06, wire I30, electric motor 5I, wire I3I, wire I28 andwire I29 to the line wire I I0 to cause energization of the electricmotor 5| to cause operation of the fan 49 of the air conditioning unit45.

From the above it is seen that for winter operation when the thermostatcalls for heat to move the contact 93 into engagement with the contact94, the circulating pump 31 is operated to cause circulation of theheating fluid through the heat exchanger 46 and the electric motor 5Iwill be energized to cause operation of the fan 49 to force air over theheat exchanger 46 and deliver this heated air to the rooms C and D tocause heating thereof. When the temperature rises above a predeterminedvalue so as to move contact 93 into engagement with contact 95, themotor 44 is deenergized to cause stopping of the circulating pump 31 andthe motor 5I is deenergized to cause stopping of operation of the fan 49whereby heating fluid is not supplied to the heat exchanger 46 andwhereby air is not passed overthe heat exchanger 46 or delivered to therooms 0 and D. For summer operation, when the temperature of the room Cis above a predetermined value, contact 93 of the thermostat 9| is movedinto engagement with the contact 95 to move switch arms I04, I05 and I06into engagement with the contacts I01, I09 and I09 to cause operationoi. the circulating pump 31 and the fan 49 of the air conditioning unit45 to deliver cooled air to the rooms C and D to lower the temperaturethereof. When the temperature in the room C falls below a predeterminedvalue, the contact 93 of the thermostat 9I is moved into engagement withthe contact 94 to move the switch arms I04, I05 and I06 out ofengagement with the contacts I01, I09 and I09 respectively to stopoperation of the circulating pump 31 and the fan 49 to stop delivery ofthe cooled air to the rooms C and D.

Located in the room C is a humidity responsive device I33 of usualdesign, containing a switch which is moved to closed position when therelative humidity of the room decreases below a predetermined value andwhich is moved to open position when the relative humidity of the roomincreases above a predetermined value. The humidity responsive deviceI33 is connected to the switch arm I06 by means of a wire I34 and thehumidity responsive device I33 is also connected by means of a wire I35to the motor device or solenoid 51. The solenoid 51 is also connected bymeans of a wire I36 to a contact I31. Cooperating with the contact I31is a manually operated switch arm I38 which is connected by means 01 awire I39 to the connection of wires I29 and I29.

When. the parts are adjusted for winter operation, the switch arm I38 ismoved into engagement with contact I31 and when the room thermostatcalls for heat so as to move switch arm I96 into engagement with contactI99 and when the relative humidity of the room C is below apredetermined value, a circuit is completed from the line wire IIIthrough wire I23, wire I25, contact I99, switch arm I96, wire I34,humidity responsive device I33, wire I35, solenoid 51, wire I36, contactI31, switch arm I38, wire I39 and wire I29 to the line wire H0.Completion of the above-circuit causes energization of the solenoid 51which causes opening of the valve 56 to admit water to the humidifyingspray device 55 to add water vapor to the heated air delivered to therooms C and D. If the relative humidity of the room rises above apredetermined. value, the

humidity responsive device I33 opens the above circuit to causedeenergization of the solenoid 51 to close the valve 56 to stopoperation of the humidifying spray device 55. Also, if the temperaturein the room C rises above a predetermined amount so as to move switcharm I96 out of engagement with contact I09, the above circuit is brokento causedeenergization of solenoid 51 to close the valve56 to stophumidifying spray 55.

Since it is not advisable to add water vapor to operation of the the airdelivered to the rooms C and D for sum- 7 cause circulation of theheating fluid through the radiators 32 in rooms A and B to cause heatingthereof by direct radiation regardless of temperature or humidityconditions existing in rooms C and D. Upon a rise in temperature in roomA above a predetermined amount, the control valve- 29 is closed and thecirculating-pump 3.1 is stopped to prevent circulation of the heatingfluid through the radiators 32 of rooms A and B. When the temperature inthe room C lowers below a predetermined value, circulating pump.3'| isplaced in operation to cause circulation of heating fluid through heatexchanger 46 and the fan 49 is placed in operation to pass air over theheat exchanger 46 into the rooms C and D regardless of temperatureconditions existing in rooms Aand B. If the relative humidity in theroom C is less than a predetermined value, the humidifying spray device55 is placed in dperation to add water vapor to the heated air deliveredto the rooms and D to increase the relative humidity thereof.

When the temperature in the room C rises above a predetermined value,the circulating pump 31 is stopped to prevent circulation of the heatingfluid through the heat exchanger 46, the fan 49 is stopped to preventdelivery of air to the rooms C and D and the adding of water vapor tothe air by means of the humidifying spray device 55 is prevented.Further, if the relative humidity in the room C rises above apredetermined value, he humidifying spray device 55 is placed out ofoperation even though heated air may be supplied to the rooms C and D bythe fan 49.

From the above, it is seen that the control valve 29 is controlledsolely by the room thermostat 69 of room A and that the fan 49 iscontrolled only by the room thermostat 9| of the room C and thatcirculating pump 31 is controlled either by the room thermostat 69 ofroom A or the room theralso possible to maintain the relative humidityin the rooms C and D at a certain value regardless of the relativehumidity existing in the rooms A and B. i

A brief description of the summer operation of I the air conditioningsystem is as follows: when the temperature in room A rises above apredetermined value, the control valve 29 is opened and the circulatingpump 31 is placed in operation to cause circulation of cooling fluidthrough the radiators 32 of rooms A and B to cause cooling of theserooms'by direct radiation regardless 01 the condition existing in therooms C and D and when the temperature of the room A falls below apredetermined value, the control valve 29 is closed to preventcirculation of the cooling fluid through the radiators 32. When thetemperature in room C rises above a predetermined value, the circulatingpump 31 is placed in operation to cause circulation of the cooling fluidthrough the heat exchanger 46 and the fan 49 is placed in operation topass air over the heat exchanger 46 to deliver cooled air to the rooms Cand D. Upon a decrease in temperature, in-room C below a predeterminedvalue the fan 49 is deenergizedto stop the flow of cool air to' therooms C and D. Since the switch I38 is moved out of engagement with thecontact l3'l during summer or cooling opera tion, the humidifying spray55 is rendered inoperative by the manually operated switch arm I 36.

From the above, it is seen that I have invented an automatic zone airconditioning system wherein a room or group of rooms may be conditionedto a different degree than another room or another group of rooms andthat provision is made for winter operation and for summer operation andall that is necessary to convert the system from winter operation tosummer operation is the throwing of two reversing switches and themanual resetting of the four shut-off valves.

Various modifications may be made in the sys-v tem embodying myinvention without departing from the spirit and-scope thereof and Idesire therefore that only such limitations shall be placed thereon asare imposed by the prior art or set forth in the appended claims.

I claim as my invention:

1. In a system of the class described for conditioning a plurality 'ofrooms, a source of conditioning fluid, heat exchanger means for certainof said rooms, other heat exchanger means for otherof said rooms,conducting means between said source and, said first heat exchangermeans and between said source and said other heat exchanger means, acondition responsive device in certain of said rooms, another conditionresponsive device in other of said rooms, and means under the command ofone of said condition responsive devices for causing circulation ofcondiditioning fluid, heat exchanger means in certain of said rooms fordirectly conditioning said rooms,

of said rooms comprising a heat exchanger mechanism and air circulatingmeans, means connecting said source of conditioning fluid and the heatexchanger mechanism of said air conditioning unit, a conditionresponsive device in said certain of said rooms, and means under thecommand of said condition responsive device for causing circulation ofconditioning fluid through tioning fluid and said heat exchanger means,

an air conditioning unit for indirectly conditioning other of said roomscomprising a heat ex-\ changer mechanism and air circulating means,

means connecting said source of conditioning fluid and the heatexchanger mechanism of said air conditioning unit, a conditionresponsive device in said certain of said rooms, another conditionresponsive device in said other of said rooms, and means under thecommand of one of said condition responsive devices for causingcirculation of conditioning fluid through said heat exchanger means andthe heat exchanger mechanism of said air conditioning unit and under thecommand of the other condition responsive device for causing circulationof conditioning fluid through the heat exchanger mechanism oi. said airconditioning unit and operation of the air circulating means.

4. In a system of the class described for conditioning a plurality ofrooms; a source of conditioning fluid, heat exchanger means for certainof said rooms, conducting means between said source and said heatexchanger means, a control device in said conducting means, other heatexchanger means for other of said rooms, conducting means between saidsource-and said other heat exchanger means, a condition responsivedevice in said certain of said rooms, a condition responsive device insaid other of said rooms, circulating means for circulating conditioningfluid through said conducting means, means responsive to one of saidcondition responsive devices and associated with said control device andsaid circulating means for circulating conditioning fluid through saidheat exchangers for all of said rooms, and means responsive to the otherof said condition responsive devices and associated with saidcirculating means for circulating fluid through said heat exchangers forsaid other of said rooms.

5. In a system of the class described for conditioning a plurality ofrooms, a source of conditioning fluid, heat exchanger means in certainof said rooms for directly conditioning said ,rooms, conditioning fluidconducting means between said source and said heat exchanger means, acontrol device in laid conditioning fluid conducting means, an airconditioning unit for indirectly conditioning other of said roomscomprising a heat exchanger mechanism and air circulating means,conditioning fluid conducting means between said source and the heatexchanger mechanism of said air conditioning unit, a conditionresponsive device in said certain of said rooms, a condition responsivedevice in said other of said rooms, circulating means for circulatingconditioning fluid through said conditioning fluid conducting means,means associated with one of said condition responsive devices, 5

said control device and said circulating means for circulatingconditioning fluid through said heat exchangers and the heat exchangermechanism of said air conditioning unit, and means associated with theother condition responsive l0 device and said circulating means forcausing circulation of heating fluid through the heat exchangermechanism of said air conditioning unit.

6. In a system of the class described for con- 15 ditioning a pluralityof rooms, a source of conditioning fluid, heat exchanger means incertain of said rooms, conditioning fluid conducting -means between saidsource and said heat exchanger means, a control device in said condi- 20tioning fluid conducting means, an air conditioning unit for other ofsaid rooms comprising a heat exchanger and an air circulating means fordelivering conditioned air to said other rooms,

conditioning fluid conducting means between said 25 source and said heatexchanger of said air con.- ditioning unit, a condition responsivedevice in said certain of said rooms, another condition responsivedevice in said other of said rooms,

circulating means for circulating conditioning 30 fluid through saidconditioning fluid conducting means, means operatively connected to oneoi said condition-responsive devices, said control device and saidcirculating means for circulating conditioning fluid through said heatex- 35 changer means for conditioning said certain of said rooms, andmeans operatively connected to said other condition responsive device,said circulating means and said air circulating means for causingcirculation of conditioning fluid,

through said heat exchanger of said air conditioner and to causedelivery of conditioned air to said other of said rooms.

'7. In a system of the class described for conditioning a plurality ofrooms, heat exchanger 45 means for certain of said rooms, a controldevice for said heat exchanger means, an air conditioning unit for otherof said rooms comprising a heat exchanger and a fan, circulating meansfor circulating heating fluid through said 50 'heat exchanger means andthrough said heat perature to cause circulation of heating fluid sothrough said heat exchanger and to pass air over said heat exchangerwhereby said other rooms are heated, means for stopping the supply ofheating fluid and for supplying cooling fluid to said heat exchangermeans and said heat ex- 65 changer of said air conditioning unit, andmeans for reversing the action 01' said thermostats when cooling fluidis supplied to said heat exchanger means and said heat-exchanger of saidair conditioning unit. I

' 70 8. In a system of the class described for conditioning a pluralityof rooms, radiators for certain of said rooms, a control device for saidradiators, an air conditioning unit ior other of said rooms comprising aheat exchanger, a fan and humidifying means, a humidity responsivedevice in the other of said rooms ior'controlling theoperation of saidhumidifying means, circulating means for circulating heating fluidthrough said radiators and said heat exchanger, a thermostat in certainof said rooms responsive to a decrease in temperature to operate saidcontrol device and said circulating means to, circulate heating fluidthrough said radiators to.

heat the certain of said rooms, a thermostat in the other of said roomsresponsive i v a decrease in temperature to condition said humidityresponsive device for operation and to operate said circulating meansand said fan to circulate heating fluid through said heat exchanger andto pass air over said heat exchanger to the other of said rooms, meansfor stopping the supply of heating fluid and for supplying cooling fluidto said radiators and said heat exchanger, and means for reversingtheaction of said thermostats when cooling fluid is supplied to saidradiators and said heat exchanger of said air conditioning unit.

9. In a system of the class described for conditioning a plurality ofrooms, radiators for certain of said rooms, a control device for saidradiators, an air conditioning unit for other of said rooms comprising aheat exchanger, a fan and humidifying means, a humidity responsivedevice in the other of said rooms for controlling the operation of saidhumidifying means, circulating means for circulating heating fluidthrough said radiators and said heat exchanger, a thermostat in certainof said rooms responsive to a decrease in temperature to operate saidcontrol device and said circulating means to circulate heating fluidthrough said radiators to heat the certain of said rooms, a thermostatin the other of said rooms responsive to a decrease in temperature tocondition said humidity responsive device for operation and to operatesaid circulating means and said fan to circulate heating fluid throughsaid heat exchanger and to pass air over said heat exchanger to theother of said rooms, means for stopping the supply of heating fluid andfor supp y cooling fluid to said radiators and said heat exchanger,means for reversing the action of said thermostats when cooling fluid issupplied to said radiators and said heat exchanger of said airconditioning unit and means for rendering said humidity responsivedevice inoperative when cooling fluid is supplied to said heatexchanger.

10. In a system of the class described for conditioning -a plurality ofrooms. heat exchanger means for certain of said rooms, an airconditioning unit for other of said rooms comprising a'heat exchangerand a fan, means for controlling the circulation of heating fluidthrough said heat exchanger means and through said heat exchanger oisaid air conditioning unit,

a thermostat in certain of said rooms associatedwith said circulationcontrolling means responsive to a decrease in temperature to causecirculation of heating fluid through said heat exchanger means, athermostat in other of said rooms associated with said circulationcontrolling means and said fan and responsive to a decrease intemperature to cause circulation of heating fluid through said heatexchanger and to pass air over said heat exchanger whereby said otherrooms are heated, means ifor stopping the supply of heating fluid andfor supplying cooling fluid to said heat exchanger means and said heatexchanger of said air conditioning unit, and means for reversing theaction'of said thermostats when cooling fluid is supplied to said heatexchanger means and said'heat exchanger of said air conditioning unit. r

11. In a system of the class described for conditioning a plurality ofrooms, flrst heat exchanger means for certain of said rooms, a secondheat exchanger means for other of said rooms, circulation controllingmeans for controlling the circulation of heating fluid through saidheatexchanger means, a thermostat responsive to a decrease intemperature in said certain rooms for controlling said circulationcontrolling means to increase the circulation of heating fluid throughsaid flrst heat exchanger means, a thermostat responsive to a decreasein temperature in the other rooms for controlling said circulationcontrolling means to increase the circulation or heating fluid throughsaid second heat exchanger means, means for stopping the supp y ofheating fluid and for supplying cooling fluid to said heat exchangermeans, and means for reversing the action of said thermo'stats whencooling fluid is supplied.

ARTHUR 6. GRANT.

